lavc/aac_ac3_parser: fix potential overflow when averaging bitrate

The new code is analog to how it's done in our mpegaudio parser.

Acked-by: Jun Zhao <barryjzhao@tencent.com>
Signed-off-by: Alexander Strasser <eclipse7@gmx.net>

diff --git a/libavcodec/aac_ac3_parser.c b/libavcodec/aac_ac3_parser.c
index 0746798dabd86e99b13f217c063631594b2e3863..e5d4b53339000ce657f23591ee497bb13bb4453b 100644 (file)
--- a/libavcodec/aac_ac3_parser.c
+++ b/libavcodec/aac_ac3_parser.c
@@ -100,9 +100,8 @@ get_next:
         /* Calculate the average bit rate */
         s->frame_number++;
         if (avctx->codec_id != AV_CODEC_ID_EAC3) {
-            avctx->bit_rate =
-                (s->last_bit_rate * (s->frame_number -1) + s->bit_rate)/s->frame_number;
-            s->last_bit_rate = avctx->bit_rate;
+            avctx->bit_rate +=
+                (s->bit_rate - avctx->bit_rate) / s->frame_number;
         }
     }
 

diff --git a/libavcodec/aac_ac3_parser.h b/libavcodec/aac_ac3_parser.h
index b04041f69d202034135812e45951f82f38d0be9e..8b93cbf84f43dc21f79fe740161ccc1cc1422bf2 100644 (file)
--- a/libavcodec/aac_ac3_parser.h
+++ b/libavcodec/aac_ac3_parser.h
@@ -56,7 +56,6 @@ typedef struct AACAC3ParseContext {
 
     int need_next_header;
     int frame_number;
-    int last_bit_rate;
     enum AVCodecID codec_id;
 } AACAC3ParseContext;
 

diff --git a/tests/ref/fate/adtstoasc_ticket3715 b/tests/ref/fate/adtstoasc_ticket3715
index 3b473ee99e3451b615218aed687f0bac6e750dbe..fbdeeb05823f5fc284994a448479aaf6f2f038e0 100644 (file)
--- a/tests/ref/fate/adtstoasc_ticket3715
+++ b/tests/ref/fate/adtstoasc_ticket3715
@@ -1,4 +1,4 @@
-3e63cbb6bb6ec756d79fab2632fef305 *tests/data/fate/adtstoasc_ticket3715.mov
+29ef0632a8eb5c336bf45a1d5076626e *tests/data/fate/adtstoasc_ticket3715.mov
 33324 tests/data/fate/adtstoasc_ticket3715.mov
 #extradata 0:        2, 0x00340022
 #tb 0: 1/44100